one nasty sugar rocket

[r1dermon]

ah yes, the famous...NOS!! thats the funny thing about n2o, a lot of morons with cars tell me how they're going to run their car on nitrous alone...well, thats all well and good, except, n2o wont combust without some sort of fuel...and the sole purpose for it in a car is to add more oxygen molecules per sq. inch. this in turn leans out the A/F mixture and allows for a larger explosion. i wouldnt try n2o in a rocket, i have no way to store it, and the 10lb bottles that i buy...i'd need to make one HUGE rocket to lift that puppy up. i used starter fluid and compressed O2 for my liquid rocket....i filled a 4oz paintball tank with both starter fluid and o2, to about 900psi. then i attached a quick disconnect airhose piece to it with a butterfly valve and a high torque servo. ignition was with two speaker wires to a 12V car battery, unfortunately this 4oz tank wouldnt fit on my scale, so i stuck it into a bag of sand, then i let her rip, i used 3 washers for the nozzle...after it lit, it stayed on for about 1/2-3/4 of a second, then KABOOM. the whole back end of the airtank blew open. i bet that puppy had some force though...possibly in the 30lb range...

[Cap'n Refsmmat]

Holy smokes!

Perhaps you should change the fuel/air mix and get it to burn more slowly (don't open the valve as wide) and you could REALLY get a powerful rocket.

 

Ever tried a can of spray paint and a match?

[jsatan]

you're crazy having o2 under pressure makes it very dangerous indeed, most things will burn in a compressed o2 atmosphere, when you're filling the tank it heats up, watch your self this can make a bomb which would blow away some body parts if not carful, please don't mix them together.

 

Just look at it in the same way a diesel engine works, no spark just pressure, boom.

js

[Primarygun]

Is N2O a strong laughing gas too>?

[jsatan]

yep, the dentist use it.

[r1dermon]

laughing gas is an overexaggeration...i've breathed it in and it wasnt that bad, (ps, for safetys sake, dont breath it in direct from the bottle...your lips would freeze to the nozzle and your lungs would freeze as well....instead, fill a balloon about half way and allow it to warm up, then breath it in....

i took into consideration the heating of o2 under compression, thats why i only filled it to 1000psi in an 1800psi tank. the tank needs to be modified in order for it to spray both fluid and o2, for this you will need airsmithing tools. two copper or aluminum tubes, and some JB weld. plus all the required fittings, which arent easy or cheap to find, especially the one from the tank to the disconnect. unfortunately, i have no idea where to find one, this fitting came from a machine shop that my dad had reposessed. probably attainable from a good airsmith. anyway, you need one pipe on the inside of the tank to go all the way to the bottom, and one to go half an inch from the top, then they both get arc welded to the nozzle fitting, this way, the rocket motor will function in both upright and up-side-down positions. i used washers for the nozzles and i didnt ignite the mix until after it had passed through the nozzle, that way(i figured) it wouldnt back-up into the tank. though it ended up happening anyway. if i made a liquid rocket again, it wouldnt be as jerry rigged, and it would probably have two seperate tanks...and i would definately use something better than starter fluid.

cap'n, spray paint is nothing, i've kept a can of WD-40 burning for over a minute at a time...WD-40 burns nice and slow, but it keeps going....only problem is start low, because fire rises and once it starts raising the flame up...you can't keep it down.

[driveit]

i am thinking off building one off these rocket engines BUT i want the case to be desposible and the rocket too... so what i was thinking for a cheap solution was MAYBE... i could use duct tape (tightly rapped), I know this is probaly the stupidest thing i ever said but, would it work? (doughts) if not do you guys have any suggestions...

[akcapr]

Just use like the brown paper stuff u get at the grocery store. Roll it up on a stick while adding elmers glue.

[vrus]

What is Sulphur's function in the mixture ? Is there anything commonly available that can replace Potassium Nitrate ? (And Sulphur)

[RyanJ]

What is Sulphur's function in the mixture ? Is there anything commonly available that can replace Potassium Nitrate ? (And Sulphur)

 

 

I think they are both needed. I'm not shure but there should be other mixtures out there - try a Google search and see what it turns up

 

Cheers,

 

Ryan Jones

[jdurg]

What is Sulphur's function in the mixture ? Is there anything commonly available that can replace Potassium Nitrate ? (And Sulphur)

 

Sulphur's function in black powder is to provide a pathway for the oxidation of carbon to CO2 by the potassium nitrate, and to help form a counter-ion for the potassium atoms in the potassium nitrate. When you think about what happens when black powder burns, you have carbon, KNO3, and Sulfur reacting with each other. The reaction products are basically carbon dioxide, nitrogen gas, and some sulfides. A little bit of the sulfur gets oxidized to SO2 gas as well, but the majority of the products are N2, CO2, and K2S. The sulfur gets reduced to the sulfide ion which binds with the potassium leftover from the potassium nitrate. Without the sulfur, the potasium would have nothing to bind with except for perhaps oxygen, and then the oxygen couldn't bind with the carbon and much of the energy would be lost.

[Halash]

holy shmoly! i made a rocket just like that with the exact same ratio!!!!!!!!! i make a nozzle out of this endcap with a hole in it i filled the pipe with the mixture and i videoed it. it made a huge flame maybe 4-5ft tall and it burned for about 5 seconds. it made a big pop at the end and when i looked at it it had propelled itself a foot into the dirt that i put it in!!!!!!!! (i stood it upright)

 

i think the big pop at the end was some piece of unreacted sugar or potassium nitrate blocking the exit hole. it biult up massive pressure for a fraction of a second and then blew it out.!!!!

 

i was scared crappless!!!!!! i thought i had made a bomb!!!!!!! it was loud as hell!

[Halash]

where'd you get your nitrate?

you can get it at home depot. it is labeled as grants stump remover. it is about 5 buck and it is 99% potassium nitrate.

[driveit]

if i added water to the KNO3/sugar/sulfur mix would it make a paste and would it ignite afterwards??

[Halash]

if i added water to the KNO3/sugar/sulfur mix would it make a paste and would it ignite afterwards??

i just just use a few drops of glue and maybe a little water. (teaspoon of glue:teaspoon of water:100 grams of rocket fuel... vary it a little becuase i am not sure if these are correct

[YT2095]

use a binder with it, red gum is ok, but it gets a bit too sticky, Dextrin is the best, and don`t use pure water, you need a little alcohol in there too, it acts as a wetting agent by breaking the surface tensions around the particles, then mix it in a plastic bag so it`s like a crumbly dough.

then press that mixture really hard into your rocket case (remembering it`ll need a hollow core).

them leave it in a warm dry place for a few days to set solid, these make fantastic engines!

[oppie]

why wouldnt the core collapse if your useing a rocket fuel like nitrate/sugar/sulfur ? Its like dust isnt it

[akcapr]

If u make your fuel putty like material or use a binder (which makes the propellant hard) or make it into "candy" it wont collapse.

[[w00t]]

I was reading somewhere that cornflour in america is diffrent to Cornflour in Britain...I live in Australia, i got a bag which says "Corn Flour" and on the back it says ingredient: Wheat Starch(Gluten) and its like 90% carbonhydrate (and no sugar)

is this correct for dextrin?

[oppie]

I cant find anywhere to buy saltpeter, ive already gone to a few different pharmacies. Any suggestions?

[pyromaster22]

the sulphur in the fuel is not necessary but i dont know wether it affects performance or not.. the propellant can be used as 65/35 kno3/sugar respectively with a few % of iron oxide catalyst.. that way you dont have to melt the ingridients either. the core does not collapse because the propellant is compressed inside the tube and so is not soft and crumbly..

[[w00t]]

it colapses on me, the dextrin method isnt as great as YT2095 says it is, i find that melting the ingredients pyromaster22 has given works nicely and much better than just leaving it as powder

[YT2095]

']I was reading somewhere that cornflour in america is diffrent to Cornflour in Britain...I live in Australia' date=' i got a bag which says "Corn Flour" and on the back it says ingredient: Wheat Starch(Gluten) and its like 90% carbonhydrate (and no sugar)

is this correct for dextrin?[/quote']

 

nope, I wouldn`t use that, it has to be cornflour 100%.

 

'']it colapses on me, the dextrin method isnt as great as YT2095 says it is

 

How would you know if you haven`t used it? Wheat Starch will NOT make dextrin. so I`m not surprised at all if it didn`t work, we`re making a solid Fuel grain here, not baking a cake!

 

edit: you can reject my advice if you like, but if it`s good enough for Estes: http://www.estesrockets.com/History1022.html

it`s good enough for anyone that`s serious about rocketry!

[nitsujbcnu]

hi guys. so i have been watching youtube like everyone else in the world lol and i have come across this kno3 model rocket tutorial. so i got my Stump remover (kno3) and i have pounded kitty litter into the 1/2" pvc tube, making my top end plug about 1/2" thick. then about 4" of the kno3 mixture w/ regular sugar. finishing with kitty litter and drilling a hole for the nozzle about half way through the engine. my problem is this. it burns for a very long time about 30 secs or more. but it doesnt go anywhere. just sits there happily melting my pvc. so i find myself wondering would powdered sugar work better and get me that boost to launch...? No it wont even stay lit. so i am feeling kinda sad because i cant launch my rocket. please help me...